Abstract: Objective To establish a new high performance liquid chromatography(HPLC) method for determining the concentration of cefazolin, cefradine, cefoperazone and cefotaxime in blood and urine, as well as to investigate its applicability. Methods Protein in blood and urine was precipitated directly by acetonitrile with acetanilide was used as the internal standard using Agilent Zorbax SB-Aq column(250 mm× 4.6 mm,5 μm). The mixed solvents of water(triethylamine 0.12%, acetic acid 0.12%) and acetonitrile were used as the mobile phase to separate cephalosporins using gradient elution method at 1 mL/min (flow rate) and 254 nm(detection wavelength). Results The working curve of four cephalosporins showed a good cor- relation (r=0.999 3), with the detection limit up to 0.01 μg/mL. The recovery rate was more than 81.2%. Conclusion This method is fast, easy and accurate. It is suitable for biological analysis of the 4 cephalosporins of the blood and urine in practical cases.

Key words: forensic toxicology, cephalosporins, blood, urine, high-performance liquid chromatography (HPLC)